sys/netproto/ipx/ipx_input.c

   1 /*
   2  * Copyright (c) 1995, Mike Mitchell
   3  * Copyright (c) 1984, 1985, 1986, 1987, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by the University of
  17  *      California, Berkeley and its contributors.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)ipx_input.c
  35  *
  36  * $FreeBSD: src/sys/netipx/ipx_input.c,v 1.22.2.2 2001/02/22 09:44:18 bp Exp $
  37  * $DragonFly: src/sys/netproto/ipx/ipx_input.c,v 1.5 2003/09/15 23:38:15 hsu Exp $
  38  */
  39
  40 #include <sys/param.h>
  41 #include <sys/systm.h>
  42 #include <sys/mbuf.h>
  43 #include <sys/protosw.h>
  44 #include <sys/socket.h>
  45 #include <sys/kernel.h>
  46 #include <sys/random.h>
  47 #include <sys/sysctl.h>
  48
  49 #include <net/if.h>
  50 #include <net/route.h>
  51 #include <net/netisr.h>
  52 #include <net/intrq.h>
  53
  54 #include "ipx.h"
  55 #include "spx.h"
  56 #include "ipx_if.h"
  57 #include "ipx_pcb.h"
  58 #include "ipx_var.h"
  59
  60 int     ipxcksum = 0;
  61 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, checksum, CTLFLAG_RW,
  62            &ipxcksum, 0, "");
  63
  64 static int      ipxprintfs = 0;         /* printing forwarding information */
  65 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxprintfs, CTLFLAG_RW,
  66            &ipxprintfs, 0, "");
  67
  68 static int      ipxforwarding = 0;
  69 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxforwarding, CTLFLAG_RW,
  70             &ipxforwarding, 0, "");
  71
  72 static int      ipxnetbios = 0;
  73 SYSCTL_INT(_net_ipx, OID_AUTO, ipxnetbios, CTLFLAG_RW,
  74            &ipxnetbios, 0, "");
  75
  76 union   ipx_net ipx_zeronet;
  77 union   ipx_host ipx_zerohost;
  78
  79 union   ipx_net ipx_broadnet;
  80 union   ipx_host ipx_broadhost;
  81
  82 struct  ipxstat ipxstat;
  83 struct  sockaddr_ipx ipx_netmask, ipx_hostmask;
  84
  85 static  u_short allones[] = {-1, -1, -1};
  86
  87 struct  ipxpcb ipxpcb;
  88 struct  ipxpcb ipxrawpcb;
  89
  90 static int ipxqmaxlen = IFQ_MAXLEN;
  91 static struct ifqueue ipxintrq;
  92
  93 long    ipx_pexseq;
  94 const int ipxintrq_present = 1;
  95
  96 static  void ipxintr(struct mbuf *);
  97 static  int ipx_do_route(struct ipx_addr *src, struct route *ro);
  98 static  void ipx_undo_route(struct route *ro);
  99 static  void ipx_forward(struct mbuf *m);
 100
 101 /*
 102  * IPX initialization.
 103  */
 104
 105 void
 106 ipx_init()
 107 {
 108         ipx_broadnet = *(union ipx_net *)allones;
 109         ipx_broadhost = *(union ipx_host *)allones;
 110
 111         read_random(&ipx_pexseq, sizeof ipx_pexseq);
 112         ipxintrq.ifq_maxlen = ipxqmaxlen;
 113         ipxpcb.ipxp_next = ipxpcb.ipxp_prev = &ipxpcb;
 114         ipxrawpcb.ipxp_next = ipxrawpcb.ipxp_prev = &ipxrawpcb;
 115
 116         ipx_netmask.sipx_len = 6;
 117         ipx_netmask.sipx_addr.x_net = ipx_broadnet;
 118
 119         ipx_hostmask.sipx_len = 12;
 120         ipx_hostmask.sipx_addr.x_net = ipx_broadnet;
 121         ipx_hostmask.sipx_addr.x_host = ipx_broadhost;
 122
 123         netisr_register(NETISR_IPX, ipxintr, &ipxintrq);
 124 }
 125
 126 /*
 127  * IPX input routine.  Pass to next level.
 128  */
 129 static void
 130 ipxintr(struct mbuf *m)
 131 {
 132         struct ipx *ipx;
 133         struct ipxpcb *ipxp;
 134         struct ipx_ifaddr *ia;
 135         int len;
 136
 137         /*
 138          * If no IPX addresses have been set yet but the interfaces
 139          * are receiving, can't do anything with incoming packets yet.
 140          */
 141         if (ipx_ifaddr == NULL)
 142                 goto bad;
 143
 144         ipxstat.ipxs_total++;
 145
 146         if ((m->m_flags & M_EXT || m->m_len < sizeof(struct ipx)) &&
 147             (m = m_pullup(m, sizeof(struct ipx))) == 0) {
 148                 ipxstat.ipxs_toosmall++;
 149                 return;
 150         }
 151
 152         /*
 153          * Give any raw listeners a crack at the packet
 154          */
 155         for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
 156              ipxp = ipxp->ipxp_next) {
 157                 struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
 158                 if (m1 != NULL)
 159                         ipx_input(m1, ipxp);
 160         }
 161
 162         ipx = mtod(m, struct ipx *);
 163         len = ntohs(ipx->ipx_len);
 164         /*
 165          * Check that the amount of data in the buffers
 166          * is as at least much as the IPX header would have us expect.
 167          * Trim mbufs if longer than we expect.
 168          * Drop packet if shorter than we expect.
 169          */
 170         if (m->m_pkthdr.len < len) {
 171                 ipxstat.ipxs_tooshort++;
 172                 goto bad;
 173         }
 174         if (m->m_pkthdr.len > len) {
 175                 if (m->m_len == m->m_pkthdr.len) {
 176                         m->m_len = len;
 177                         m->m_pkthdr.len = len;
 178                 } else
 179                         m_adj(m, len - m->m_pkthdr.len);
 180         }
 181         if (ipxcksum && ipx->ipx_sum != 0xffff) {
 182                 if (ipx->ipx_sum != ipx_cksum(m, len)) {
 183                         ipxstat.ipxs_badsum++;
 184                         goto bad;
 185                 }
 186         }
 187
 188         /*
 189          * Propagated (Netbios) packets (type 20) has to be handled
 190          * different. :-(
 191          */
 192         if (ipx->ipx_pt == IPXPROTO_NETBIOS) {
 193                 if (ipxnetbios) {
 194                         ipx_output_type20(m);
 195                         return;
 196                 } else
 197                         goto bad;
 198         }
 199
 200         /*
 201          * Is this a directed broadcast?
 202          */
 203         if (ipx_hosteqnh(ipx_broadhost,ipx->ipx_dna.x_host)) {
 204                 if ((!ipx_neteq(ipx->ipx_dna, ipx->ipx_sna)) &&
 205                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_broadnet)) &&
 206                     (!ipx_neteqnn(ipx->ipx_sna.x_net, ipx_zeronet)) &&
 207                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)) ) {
 208                         /*
 209                          * If it is a broadcast to the net where it was
 210                          * received from, treat it as ours.
 211                          */
 212                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 213                                 if((ia->ia_ifa.ifa_ifp == m->m_pkthdr.rcvif) &&
 214                                    ipx_neteq(ia->ia_addr.sipx_addr,
 215                                              ipx->ipx_dna))
 216                                         goto ours;
 217
 218                         /*
 219                          * Look to see if I need to eat this packet.
 220                          * Algorithm is to forward all young packets
 221                          * and prematurely age any packets which will
 222                          * by physically broadcasted.
 223                          * Any very old packets eaten without forwarding
 224                          * would die anyway.
 225                          *
 226                          * Suggestion of Bill Nesheim, Cornell U.
 227                          */
 228                         if (ipx->ipx_tc < IPX_MAXHOPS) {
 229                                 ipx_forward(m);
 230                                 return;
 231                         }
 232                 }
 233         /*
 234          * Is this our packet? If not, forward.
 235          */
 236         } else {
 237                 for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 238                         if (ipx_hosteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) &&
 239                             (ipx_neteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) ||
 240                              ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)))
 241                                 break;
 242
 243                 if (ia == NULL) {
 244                         ipx_forward(m);
 245                         return;
 246                 }
 247         }
 248 ours:
 249         /*
 250          * Locate pcb for datagram.
 251          */
 252         ipxp = ipx_pcblookup(&ipx->ipx_sna, ipx->ipx_dna.x_port, IPX_WILDCARD);
 253         /*
 254          * Switch out to protocol's input routine.
 255          */
 256         if (ipxp != NULL) {
 257                 ipxstat.ipxs_delivered++;
 258                 if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS) == 0)
 259                         switch (ipx->ipx_pt) {
 260                         case IPXPROTO_SPX:
 261                                 spx_input(m, ipxp);
 262                                 return;
 263                         }
 264                 ipx_input(m, ipxp);
 265         } else
 266                 goto bad;
 267
 268         return;
 269
 270 bad:
 271         m_freem(m);
 272 }
 273
 274 void
 275 ipx_ctlinput(cmd, arg_as_sa, dummy)
 276         int cmd;
 277         struct sockaddr *arg_as_sa;     /* XXX should be swapped with dummy */
 278         void *dummy;
 279 {
 280         caddr_t arg = (/* XXX */ caddr_t)arg_as_sa;
 281         struct ipx_addr *ipx;
 282
 283         if (cmd < 0 || cmd > PRC_NCMDS)
 284                 return;
 285         switch (cmd) {
 286                 struct sockaddr_ipx *sipx;
 287
 288         case PRC_IFDOWN:
 289         case PRC_HOSTDEAD:
 290         case PRC_HOSTUNREACH:
 291                 sipx = (struct sockaddr_ipx *)arg;
 292                 if (sipx->sipx_family != AF_IPX)
 293                         return;
 294                 ipx = &sipx->sipx_addr;
 295                 break;
 296
 297         default:
 298                 if (ipxprintfs)
 299                         printf("ipx_ctlinput: cmd %d.\n", cmd);
 300                 break;
 301         }
 302 }
 303
 304 /*
 305  * Forward a packet. If some error occurs drop the packet. IPX don't
 306  * have a way to return errors to the sender.
 307  */
 308
 309 static struct route ipx_droute;
 310 static struct route ipx_sroute;
 311
 312 static void
 313 ipx_forward(m)
 314 struct mbuf *m;
 315 {
 316         struct ipx *ipx = mtod(m, struct ipx *);
 317         int error;
 318         struct mbuf *mcopy = NULL;
 319         int agedelta = 1;
 320         int flags = IPX_FORWARDING;
 321         int ok_there = 0;
 322         int ok_back = 0;
 323
 324         if (ipxforwarding == 0) {
 325                 /* can't tell difference between net and host */
 326                 ipxstat.ipxs_cantforward++;
 327                 m_freem(m);
 328                 goto cleanup;
 329         }
 330         ipx->ipx_tc++;
 331         if (ipx->ipx_tc > IPX_MAXHOPS) {
 332                 ipxstat.ipxs_cantforward++;
 333                 m_freem(m);
 334                 goto cleanup;
 335         }
 336
 337         if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute)) == 0) {
 338                 ipxstat.ipxs_noroute++;
 339                 m_freem(m);
 340                 goto cleanup;
 341         }
 342         /*
 343          * Here we think about  forwarding  broadcast packets,
 344          * so we try to insure that it doesn't go back out
 345          * on the interface it came in on.  Also, if we
 346          * are going to physically broadcast this, let us
 347          * age the packet so we can eat it safely the second time around.
 348          */
 349         if (ipx->ipx_dna.x_host.c_host[0] & 0x1) {
 350                 struct ipx_ifaddr *ia = ipx_iaonnetof(&ipx->ipx_dna);
 351                 struct ifnet *ifp;
 352                 if (ia != NULL) {
 353                         /* I'm gonna hafta eat this packet */
 354                         agedelta += IPX_MAXHOPS - ipx->ipx_tc;
 355                         ipx->ipx_tc = IPX_MAXHOPS;
 356                 }
 357                 if ((ok_back = ipx_do_route(&ipx->ipx_sna,&ipx_sroute)) == 0) {
 358                         /* error = ENETUNREACH; He'll never get it! */
 359                         ipxstat.ipxs_noroute++;
 360                         m_freem(m);
 361                         goto cleanup;
 362                 }
 363                 if (ipx_droute.ro_rt &&
 364                     (ifp = ipx_droute.ro_rt->rt_ifp) &&
 365                     ipx_sroute.ro_rt &&
 366                     (ifp != ipx_sroute.ro_rt->rt_ifp)) {
 367                         flags |= IPX_ALLOWBROADCAST;
 368                 } else {
 369                         ipxstat.ipxs_noroute++;
 370                         m_freem(m);
 371                         goto cleanup;
 372                 }
 373         }
 374         /*
 375          * We don't need to recompute checksum because ipx_tc field
 376          * is ignored by checksum calculation routine, however
 377          * it may be desirable to reset checksum if ipxcksum == 0
 378          */
 379 #if 0
 380         if (!ipxcksum)
 381                 ipx->ipx_sum = 0xffff;
 382 #endif
 383
 384         error = ipx_outputfl(m, &ipx_droute, flags);
 385         if (error == 0) {
 386                 ipxstat.ipxs_forward++;
 387
 388                 if (ipxprintfs) {
 389                         printf("forward: ");
 390                         ipx_printhost(&ipx->ipx_sna);
 391                         printf(" to ");
 392                         ipx_printhost(&ipx->ipx_dna);
 393                         printf(" hops %d\n", ipx->ipx_tc);
 394                 }
 395         } else if (mcopy != NULL) {
 396                 ipx = mtod(mcopy, struct ipx *);
 397                 switch (error) {
 398
 399                 case ENETUNREACH:
 400                 case EHOSTDOWN:
 401                 case EHOSTUNREACH:
 402                 case ENETDOWN:
 403                 case EPERM:
 404                         ipxstat.ipxs_noroute++;
 405                         break;
 406
 407                 case EMSGSIZE:
 408                         ipxstat.ipxs_mtutoosmall++;
 409                         break;
 410
 411                 case ENOBUFS:
 412                         ipxstat.ipxs_odropped++;
 413                         break;
 414                 }
 415                 mcopy = NULL;
 416                 m_freem(m);
 417         }
 418 cleanup:
 419         if (ok_there)
 420                 ipx_undo_route(&ipx_droute);
 421         if (ok_back)
 422                 ipx_undo_route(&ipx_sroute);
 423         if (mcopy != NULL)
 424                 m_freem(mcopy);
 425 }
 426
 427 static int
 428 ipx_do_route(src, ro)
 429 struct ipx_addr *src;
 430 struct route *ro;
 431 {
 432         struct sockaddr_ipx *dst;
 433
 434         bzero((caddr_t)ro, sizeof(*ro));
 435         dst = (struct sockaddr_ipx *)&ro->ro_dst;
 436
 437         dst->sipx_len = sizeof(*dst);
 438         dst->sipx_family = AF_IPX;
 439         dst->sipx_addr = *src;
 440         dst->sipx_addr.x_port = 0;
 441         rtalloc(ro);
 442         if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
 443                 return (0);
 444         }
 445         ro->ro_rt->rt_use++;
 446         return (1);
 447 }
 448
 449 static void
 450 ipx_undo_route(ro)
 451 struct route *ro;
 452 {
 453         if (ro->ro_rt != NULL) {
 454                 RTFREE(ro->ro_rt);
 455         }
 456 }
 457
 458 void
 459 ipx_watch_output(m, ifp)
 460 struct mbuf *m;
 461 struct ifnet *ifp;
 462 {
 463         struct ipxpcb *ipxp;
 464         struct ifaddr *ifa;
 465         struct ipx_ifaddr *ia;
 466         /*
 467          * Give any raw listeners a crack at the packet
 468          */
 469         for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
 470              ipxp = ipxp->ipxp_next) {
 471                 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
 472                 if (m0 != NULL) {
 473                         struct ipx *ipx;
 474
 475                         M_PREPEND(m0, sizeof(*ipx), M_DONTWAIT);
 476                         if (m0 == NULL)
 477                                 continue;
 478                         ipx = mtod(m0, struct ipx *);
 479                         ipx->ipx_sna.x_net = ipx_zeronet;
 480                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 481                                 if (ifp == ia->ia_ifp)
 482                                         break;
 483                         if (ia == NULL)
 484                                 ipx->ipx_sna.x_host = ipx_zerohost;
 485                         else
 486                                 ipx->ipx_sna.x_host =
 487                                     ia->ia_addr.sipx_addr.x_host;
 488
 489                         if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT))
 490                             TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 491                                 if (ifa->ifa_addr->sa_family == AF_IPX) {
 492                                     ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
 493                                     break;
 494                                 }
 495                             }
 496                         ipx->ipx_len = ntohl(m0->m_pkthdr.len);
 497                         ipx_input(m0, ipxp);
 498                 }
 499         }
 500 }